Acknowledgements
The authors would like to thank Kengo Takeuchi for the pathological diagnosis and Yasuhito Suehara for performing droplet digital PCR. The authors also thank Editage (www.editage.jp) for providing English language editing services.
Author contributions
D.I. and K.M. interpreted the data, provided patient care, and wrote the manuscript. M.O., A.U., R.T., K.N., and M.T. provided patient care.
Consent form
The patient provided written informed consent.
Disclosure statement
The authors report there are no competing interests to declare.